If multimorbidity (multiple medical conditions in an individual) is to be prevented, it is important to identify the characteristics that contribute to it. Results of a 10-year study find that, for adults age 50 and older, risks of developing multimorbidity are positively associated with age and are higher for those with low socioeconomic status, obesity, low level of physical activity, or an external locus of control (believing that life events are outside of their control). No significant associations were observed for sex, educational attainment, or social detachment. The authors suggest that future work to reduce the incidence of multimorbidity should promote healthy lifestyles while targeting an internal locus of control in order to empower patients to achieve and maintain behavior change with the potential for synergistic effects.